Poly(organotin) mercaptide polymers and resins stabilized therewith

ABSTRACT

Poly(organotin) mercaptide condensation polymers useful as stabilizer for vinyl resins are prepared by reacting an organotin compound with a polyfunctional polymercapto ester derived from a polyhydric alcohol containing more than two hydroxyl groups, which is esterified with a mercapto acid so as to leave one hydroxyl group unesterified, and the latter is esterified with an aliphatic or aromatic monocarboxylic acid.

United States Patent Fath et al.

[54] POLY(ORGANOTIN) MERCAPTIDE POLYMERS AND RESINS STABILIZED THEREWITH[72] Inventors: Joseph F ath; Donald L. Deardorff, both of Barrington,R.l.

[52] U.S. Cl ..260/399, 260/23, 260/429.7,

260/476, 260/491, 260/410.6 [51] Int. Cl. ..C08f 45/62 [58] Field ofSearch ..260/399 1 June 13, 1972 [56] References Cited UNITED STATESPATENTS 2,648,650 8/1953 Weinberg et a] ..260/30.6 3,158,576 11/1964Rude] et al ..252/48.6

Primary Examiner-Elbert L. Roberts Attorneyl-lugo E. Weisberger [57]ABSTRACT Poly(organotin) mercaptide condensation polymers useful asstabilizer for vinyl resins are prepared by reacting an organotincompound with a polyfunctional polymercapto ester derived from apolyhydric alcohol containing more than two hydroxyl groups, which isesterified with a mercapto acid so as to leave one hydroxyl groupunesterified, and the latter is esterified with an aliphatic or aromaticmonocarboxylic acid.

12 Claims, No Drawings POLY(ORGANOTIN) MERCAPTIDE POLYMERS AND RESINSSTABILIZED THEREWITII CROSS-REFERENCE TO RELATED APPLICATION Thisapplication is a division of application Ser. No. 568,061, filed July26, 1966, now US. Pat. No. 3,518,223.

This invention relates to novel organotin bearing condensation polymersuseful in the stabilization of resins derived from ethylenicallyunsaturated compounds and to the resin compositions produced by theincorporation of this stabilizer. The organotin bearing condensationpolymers may be differently described as poly(dialkyltin) mercaptidepolymers.

It is well known that polyvinyl chloride, its copolymers, and many othervinyl halide based resins are subject to degradation and discolorationat the elevated temperatures needed for processing, and even undernormal conditions and usage beyond the manufacturing stage. A largevariety of compounds are now known which are effective in preventingthis discoloration for relatively long periods of time. Among thesestabilizer compounds, organotin derivatives have proven to be some ofthe most desirable. Examples of these organotin derivatives are found inU.S. Pats. No. 2,648,650 and No. 2,801,258. These patents discloseprocesses by which dibutyltin mercaptides are derived from the reactionof simple mercaptans, such as lauryl mercaptan, or simplemercaptoesters, with an organotin compound.

The present invention provides an improved stabilizing composition foruse in the stabilization of polyvinyl halide resins. By polyvinyl halideresins, we mean to include such resins as are obtained by polymerizingsuch monomers as vinyl chloride, vinyl fluoride, vinylidene chloride,trifluoroethylene, tetrafluoroethylene, either alone or withcopolymerizable monomers such as vinyl acetate, ethyl acrylate,acrylonitrile, etc.

The stabilizing composition is a condensation polymer containingrepeating groups of the general structural formula F I l L ll where eachR is a hydrocarbon moiety containing up to 12 carbon atoms and can bealkyl, cycloalkyl, aryl, or alkaryl and A is a polyfunctional organicradical having certain further characteristics hereinafter described ingreater detail. It will suffice at this point to state that thepolyfunctional organic radical A is derived from a polyol containingmore than two hydroxy groups wherein more than one has been estrifiedwith a mercapto acid and all or part of the remaining have beenestrified with a sulfur free organic acid. The resulting condensationpolymer can therefore be widely varied in its structure to permit it topossess valuable properties, such as controlled lubricity and fusiontime, and oxidative and light stability. At the same time, the polymericnature of these structures provides relatively lower volatility andodor, both highly desirable characteristics, especially duringprocessing of the stabilizer compounds. Moreover, the stabilizers of thepresent invention exhibit excellent thermal stability when compounded,processed, etc.

From the foregoing description of the invention, it will have becomeapparent that a major object of the invention is to provide improved tincontaining stabilizing compositions for use in polyvinyl halide resinsto prevent or retard thermal degradation of such resins.

Another and more specific object of the invention is to provide animproved stabilizer composition for polyvinyl halide polymers andcopolymers, which composition contains active organotin groups condensedwith novel polyfunctional mercaptoesters.

Another object of the invention is to provide, as a stabilizer ofpolyvinyl halide resins and polyvinyl halide copolymers, apoly(dialkyltin) mercaptide condensation polymer which possesses apolyfunctionality allowing numerous variations in the structure of thestabilizers so as to impart certain desirable properties, while fullyretaining the thermal stability characteristic commonly attributed tothe presence of the organotin group.

An additional object of the invention is to provide a novel compositionof matter useful as an intermediate in the preparation of highlyeffective stabilizing materials for stabilizing resins derived fromvinyl halides.

A further object of the invention is to provide an organotincontainingstabilizing composition for vinyl halide resins, which composition isgenerally less volatile than the organotin type stabilizers heretoforeprovided.

Additional objects and advantages will become apparent upon reading thefollowing detailed description of the invention, and referring to theappended examples of its practice.

The condensation polymers of the present invention are prepared byreacting an organotin compound, such as a dialkyl organotin oxide, or asalt thereof, with certain polyfunctional sulfur bearing compounds whichare broadly designated as (polymercapto) esters. The esters can best bedefined by their mode of derivation. First, they are derived frompolyhydric alcohols containing more than two hydroxyl groups. Thesealcohols are esterified with mercapto acids containing a sulfhydryl anda carboxylic acid group. In the esterification reaction, at least one ofthe hydroxyl groups are not so esterified. The hydroxyl groups notesterified with mercapto acid can then be esterified with a selectedcarboxylic acid, or may in whole or in part be left essentiallyunesterified. The esters thus formed may be broadly represented by thestructure )R') (Formula 1) where n is a number generally of from one to,and including, six, (preferably 1 to 4), X is a substituted acylradical, and Y is a poly substituted hydrocarbon moiety (preferablycontaining up to 12 carbon atoms) in which R is selected from the groupconsisting of hydrogen, and acyl radicals. Thus, the mercaptoesters canbe either mixed esters or partial esters, containing in either casesulfhydryl groups for subsequent condensation with organotin compounds.

The (polymercapto) esters impart great versatility to the organotinbearing condensation polymers made therefrom since the non-sulfurbearing moiety of the (polymercapto) esters can give selected compoundsvarying widely in process characteristics, or possibly even containingresidues which promote light stabilizing characteristics, improvelubricity, etc.

After formation of the complex esters, they are reacted with anorganotin compound to form condensation polymers which are thestabilizing compounds of the invention. The stabilizing compounds arethen incorporated in the vinyl resins which they are to stabilize toprovide improved, highly stabilized resinous compositions.

Since, as has been indicated, the stabilizer compositions of theinvention are formed by the reaction of organotin compounds with certain(polymercapto) esters, the latter compounds will initially be describedin detail. These (polymercapto) esters are mixed esters and are believedto be novel compositions of matter, and their polyfunctionality plays animportant role in the achievement of the objects of this invention. Theterm polyfunctionality is here intended to connote the presence both ofa plurality of sulfhydryl groups, permitting subsequent condensationwith the organotin compounds, and also at least one hydroxyl group,partially or wholly esterified.

The described polyfunctionality is achieved in preparing the(polymercapto) esters by reacting polyhydric alcohols containing morethan two hydroxyl groups with mercapto acids containing a sulfhydrylgroup as well as a carboxylic acid group. The polyhydric alcohols usedare preferably aliphatic polyols, containing from about 3 to aboutcarbon atoms. Examples of suitable alcohols which can be employed aretrimethylolpropane, pentaerythritol, di-pentaerythritol,trimethylolethane, glycerine, 1,2,6-hexanetriol, sorbitol,1,3,5-pentanetriol, l ,5,8-octanetriol, 4-ethyll ,4,8-octanetriol and3-butyl-l,2,6-heptanetriol. The mercapto acids used are preferablyaliphatic compounds, and are most preferably mercaptoalkanoic acidscontaining from about i to about 6 carbon atoms. Examples of suitablemercapto acids for use in the reaction are mercaptoacctic acid(thinglycolic acid), 3-mertaptnpmpiunic acid, and 4-mercaptubutyricacid.

In carrying out the esterification reaction to produce the describedpolyfunctional mercaptoester, it is essential that the number ofhydroxyl groups furnished by the polyol molecule exceed that of thenumber of carboxylic groups furnished by the mercapto acid. in this waythe unreacted hydroxyl groups can be reserved for the purpose oftailoring the properties of the mercaptoester, either by not furtherreacting the reserved hydroxyl groups at all, or by esterifying them, orsome of them, with selected carboxylic acids. Thus, for example, ahydroxyl not esterified by the mercapto acids can, if desired, beesterified by such carboxylic acids as pelargonic acid, 2- ethylhexanoicacid, lauric acid, coconut fatty acids, butyric acid, benzoic acid,para-toluic acid, para-tertiary butylbenzoic acid, salicylic,iso-decanoic acid, stearic acid, and decanoic acid. The reactionproducts of the esterification reaction will constitute equilibriummixtures which are subsequently suitable for further condensation toproduce the tin bearing polymers.

it can readily be seen that the presence of non-sulfur bearingfunctional groups permits a wide variety of compounds to be produced,and their properties and characteristics to be selectively controlled soas to permit the stabilizers to accomplish certain functions whenincorporated in the resinous materials to be stabilized. Thus, forinstance, by varying the chain length of the carboxylic acid used toesterify the reserve hydroxyl groups, and by using carboxylic acids of afatty nature, an ultimate stabilizing composition can be produced thathas a high degree of lubricity.

The final complex mercaptoesters thus contemplated for subsequentreaction with organotin compounds to produce the condensation polymerstabilizing compositions of the invention can be represented by thestructural formula( 1 where n is a number from 1 to 6, X is asubstituted acyl radical, and is preferably derived from an alkanoicacid containing from about 1 to about 6 carbon atoms, and Y is a polysubstituted hydrocarbon moiety preferably containing up to 12 carbonatoms and in which R is selected from the group consisting of hydrogen,and acyl radicals. Examples of esters of this type aretrimethylolpropane monopelargonate di(thioglycolate) trim ethylolpropanemonopelargonate di( 3-mercaptopropionate) trimethylolpropanemonopelargonate di( 4-mercaptobutyrate) pentaerythritol monopelargonatedi( thioglycolate) pentaerythritol monopelargonate di(3-mercaptopropionate) glycerol monohexanoate di( thioglycolate)trimethylolpropane monobutyrate di(thioglycolate) 1,2,6-hexanetriol di(thioglycolate) sorbitol monobutyrate monobenzoate di(4-mercaptobutyrate)pentaerythritol monopelargonate di( 4-mercaptobutyrate) pentaerythritoldi( pelargonate) di(thioglycolate) pentaerythritol monopelargonatemonobenzoate di( thioglycolate pentaerythritol monopelargonatemonosalicylate di( thioglycolate) glyceryl monopelargonatedi(thioglycolate) The mercaptoesters can be prepared by conventionalesterification procedures. In the examples of ester preparationhereinafter appearing, an appropriate polyhydric alcohol and the desiredacids are reacted by heating them together in the presence of an inertorganic solvent. The water produced in the reaction is continuouslyremoved and the reaction is continued until all of the water is removed.The reaction may be catalyzed with strong acids such as sulfuric acid,p-toluene sulfonic acid and methanesulfonic acid. The (polymercapto)esters may be recovered by removing solvent and excess acids withheating and under reduced pressure, and they may be further reacted insitu as hereinafter described to give the desired poly( tinmercaptide)derivative.

The complex mercaptoesters are reacted with organotin compounds to formcondensation polymers which we have determined to possess great value asstabilizers for polymers derived from vinyl halide resins. The preferredorganotin compounds used in the preparation of the stabilizers aredialkyltin oxides and most preferably, those in which the alkylsubstituents contain from about 4 to about 8 carbon atoms. In additionto the dialkyltin oxides, dialkyltin hydroxides, dialkyltin halides andacetates can also be utilized. The condensation reaction occuringbetween the mercaptoesters and dialkyltin oxide compounds can beillustrated in a broad and general sense by the following equation:

(Equation 1) where A is the group of Formula 1, m is a positive integerdetermined by the stoichiometry of the reactants employed and the chainlength of the condensation polymer produced, and each R is an alkylradical, preferably of 4 to 8 carbon atoms.

From the foregoing equation, it will be seen that the product of thereaction is a true condensation polymer, the structure and compositionof which are specifically defined by the stoichiometry and multiplicityof the reaction system. it can thus be seen that if approximately equalmolar ratios of the two bifunctional reactants are used, as indicated inEquation 1, very high molecular weight condensation polymers can beproduced. While being functional or operative insofar as the practice ofthis invention is concerned, such high molecular weight substances oftenhave the disadvantage of being extremely viscous, or semi-solid, andhaving a nondefinitive termination. For this reason, it is frequentlydesirable and advantageous to terminate the condensation polymers in amanner analogous to common practice in plasticizer technology. Thetermination can be accomplished by the use of monofunctionalsulfur-bearing or carboxylic acid groups as indicated in Equations (2)and (3 )1 where A is the group (XO|I-OX) (OR/)n hereinbefore defined inreference to Equation (1), R and m have the meanings hereinbeforeestablished, X is selected from the group consisting of S and and R" isselected from the group consisting of alkyl, aryl, alkylene carboxyalkylor alkylene carboxyalkoxyaryl radicals. By the use of such terminationprocedure, additional species of condensation polymers can be generatedwhich have lower molecular weights by virtue of the termination, andwhich also have lower viscosities, and are more readily controllableduring actual production. In addition to the reduction in the molecularweight of the polymers produced, the use of the termination procedurepermits further variation in the properties and performancecharacteristics of the condensation polymers since a variety ofterminating agents can be utilized. Terminating agents may, for example,be chosen from carboxylic acid, alkyl or aryl mercaptans and a number ofmono-functional mercaptoesters. Preferred terminating agents include,but are not limited to, lauryl mercaptan, C,,C n-alkyl mercaptans,tetradecyl mercaptans, stearyl mercaptan, butyl thioglycolate,phenoxyethyl thioglycolate, isooctyl thioglycolate, hexylmercaptopropionate, phenoxy ethyl mercaptopropionate, benzylmercaptopropionate, lauryl thioglycolate, pelargonic acid, benzoic acid,and other acids enumerated herein for use in the esterificationprocedure procedure to produce the mercaptoesters.

It is to be noted that while the terminated condensation polymers arethe preferred stabilizing compositions of the invention due to theadditional processing advantages they impart and incur, the invention isnot limited to such terminated polymers, but also encompasses thebroader concept of condensation polymers which are not terminated, andhave a very wide range of relatively higher molecular weights.

Among the preferred stabilizing compositions of the invention are thosederived from dibutyltin oxide, pentaerythritol, pelargonic acid andmercaptopropionic acid, such as, for example, poly(dibutyltin)[pentaerythritol(pelargonate) (mercaptopropionate)](phenoxyethylmercaptopropionate).

The stabilizing agents are prepared by heating the (polymercapto) esterand an appropriate terminating agent (if one is used as per reactions(2) to (3) with the selected organotin compound. The reaction can beconveniently carried out in the presence of an inert organic solventwhich facilitates the removal of water formed during the reaction. Thereaction may be, but is not necessarily, conducted in the presence ofacid catalysts. The poly (mercaptide) condensation polymer products arerecovered by filtration of any solid material which may be present andremoval of the solvent by heating under reduced pressure. As haspreviously been indicated, the (polymercapto) ester may be converted insitu to the condensation polymer stabilizing agent, that is, all thereactions can be performed in a single reaction vessel.

The following examples are presented in order to illustrate the mannerin which the novel (polymercapto) esters of the invention are prepared,and to further illustrate the manner in which these esters are convertedto stabilizing compositions useful in the stabilization of resins.

EXAMPLE 1 trimethylolpropane monopelargonate removed by vacuumdistillation. The product had a specific gravity of 1.1 10 at 25 C,color of 30 APHA, viscosity at 25 C of 7 1 .6 cs. and was found tocontain 15.1 weight per cent mercaptan sulfur.

EXAMPLE 2 EXAMPLE 3 Preparation of trimethylolpropane monopelargonatedi(mercaptopropionate) A mixture of 268 grams trimethylolpropane and 316grams pelargonic acid was heated five hours at 180 C in the presence ofrefluxing benzene. Mercaptopropionic acid, 475 grams, was added andreflux continued at 160 C until the theoretical amount of water ofcondensation was collected. Benzene and excess acids were removed underreduced pressure to leave 833 grams oil product containing 13.8 per centby weight mercaptan sulfur. Specific gravity 25 C 1.0830; viscosity, 25C 77 cs.; color 70 APHA.

EXAMPLE 4 Preparation of pentaerythritol monohydroxy monopelargonate di(mercaptopropionate) A mixture of 148 grams technical pentaerythritol(containing 88 per cent mono and 12 per cent dipentaerythritol), 158grams pelargonic acid and 212 grams mercaptopropionic acid was heated at140 C in the presence of refluxing benzene until all water ofcondensation was removed. Volatile components were removed under reducedpressure to give 449 grams of an oil product which contained 13.8 percent by weight mercaptan sulfur. Specific gravity at 25 C 1.1360;viscosity at 25 C 302 cs.

EXAMPLE 5 Preparation of (pentaerythritol)1.0 (pelargonate)2.0(mercaptopropionate) 1 .6

A 500 ml. flask equipped with thermometer and nitrogen sparge tube wascharged with 68.5 grams pentaerythritol, 158 grams pelargonic acid, 88grams mercaptopropionic acid, 100 grams benzene. The mixture wasrefluxed at to 150 C for twelve hours. Benzene was removed under reducedpressure. A pale yellow oil product remained having a mercaptan sulfurcontent of 9.13 per cent by weight. Specific gravity at 25 C 1.140.

EXAMPLE 6 Preparation of poly(dibutyltin)1.0(trimethylolpropanemonopelargonate dithioglycolate) 1.0

The polymercaptoester of Example 1 (231 grams) was heated with 124 gramsof dibutyltin oxide at C in the presence of refluxing benzene. Afterthree hours time all water of reaction had been removed. Benzene wasremoved under reduced pressure to leave 333 grams of a viscous yellowoil product. Specific gravity at 25 C 1.142. Tin content, calculated17.2 weight per cent.

EXAMPLE 7 Preparation of poly( dibutyltin)2.0[trimethylolpropanemonopelargonate di(thioglycolate)] 1.0 (laury1mercaptan)2.0

Polymercaptoester of Example 1 (118 grams) was heated along with 124grams of dibutyltin oxide and 103 grams of a C, primary n-alkylmercaptan for four hours at 100 C in the presence of refluxing benzene.Removal of water was complete after two hours. The mixture was filteredand benzene removed under reduced pressure to leave a slightly viscousyellow residue product. Tin content 17.3 weight per cent; calculated.

EXAMPLE 8 EXAMPLE 9 Preparation of poly( dibutyltin)2.0[trimethylolpropane monopelargonate di( thioglycolate)] 1.0 (laurylthioglycolate)2.0

A quantity of trimethylolpropane monopelargonate di(thioglycolate), (l18 grams), was mixed with 124 grams of dibutyltin oxide and 133 grams oflauryl thioglycolate and heated at 100 C for three hours in the presenceof refluxing benzene. Removal of water was complete after two hoursreaction time. Removal of benzene by heating under reduced pressure lefta yellow oil residue product with specific gravity at 25 C of 1.068. Tincontent 17.2 per cent by weight.

EXAMPLE 10 Preparation of poly(dibutyltin)2.0 [pentaerythritolmonohydroxy monopelargonate di(thioglycolate)] 1.0 (laurylthioglycolate)2.0

Polymercaptoester from Example 2 (1 13 grams) was mixed with 124 gramsof dibutyltin oxide and 133 grams lauryl thioglycolate and heated at 100C for three hours in the presence of refluxing benzene. Removal of waterwas complete after two hours. Benzene was removed by heating underreduced pressure and the product filtered to give a light yellow oilresidue product with a specific gravity at 25 C of 1.140. Tin content16.4 per cent by weight, calculated.

EXAMPLE 1 1 Preparation of poly(dibutyltin)2.0 mono-pelargonatedi(mercaptopropionate)] thioglyco-late)2.0

A quantity of trimethylolpropane monopelargonate di(mercaptopropionate),(46.3 grams), was mixed with 49.6 grams of dibutyltin oxide and 53.4grams of lauryl thioglycolate and the whole heated for two hours at 100C in the presence of refluxing benzene. Removal of water was completeafter one hour. Benzene was removed by heating under reduced pressure.Filtration left an oil product with viscosity at 25 C of 363 cs.Specific gravity at 25 C 1.040. Tin content 12.6 weight per cent.

[trimethylolpropane 1 .0 lauryl Example 12 Preparation ofpoly(dibutyltin)2.0 [pentaerythritol monohydroxy monopelargonatedi(mercaptopropionate)]1.0 (lauryl thioglyco-late)2.0

A quantity of pentaerythritol monohydroxy monopelargonatedi(mercaptopropionate), (47.9 grams), was mixed with 49.6 grams ofdibutyltin oxide and 53.4 grams of lauryl thioglycolate and the wholeheated for 2.5 hours at 100 C in the presence of refluxing benzene.Removal of water was complete after one hour. The product was filteredand benzene removed by heating under reduced pressure to leave a lightcolored oil. Viscosity at 25 C 404 cs., specific gravity at 25 C 1.10,tin content 17.2 weight per cent (calculated 15.8 per cent).

EXAMPLE 13 Preparation of poly(dibutyltin)2.0[pentaerythrito1monohydroxy monopelargonate di(mercaptopropicoate)] 1.0

( lauryl thioglyco-late)2.0 toluene-2, 4-diisocyanate)0.6

In a separate experiment, 42 grams of example 12 product were combinedwith 3 grams toluene diisocyanate and heated in a nitrogen atmosphere atC for thirty minutes. The

product was a very viscous and pale yellow oil.

EXAMPLE 14 Preparation of poly( dibutyltin )2.0 [trimethylolpropanemonopelargonate di(mercaptopropionate)] 1.0 (isoctylthioglyco-late )2.0

A quantity of trimethylolpropane monopelargonate di(mercaptopropionate,(46.3 grams), was mixed with 49.6 grams of dibutyltin oxide and 41.5grams of isooctylthioglycolate and the whole heated for two hours at 100C in the presence of refluxing benzene. Removal of water was completeafter one hour. Filtration and removal of benzene by heating underreduced pressure left a colorless oil residue product. Viscosity at 25 Ccs., specific gravity at 25 C 1.10. Tin content 18.1 per cent by Weight.

EXAMPLE 15 Preparation of poly(dibutyltin)Sitrirnethylolpropanemonopelargonate di( mercaptopropionate 14 A quantity oftrimethylolpropane monopelargonate di(mercaptopropionate). 1 16 grams),was mixed with 74.4 grams of dibutyltin oxide and heated at 100 C forthree hours in the presence of refluxing benzene. Removal of water wascomplete after one hour. The product was filtered and benzene removed byheating under reduced pressure. The residue product was viscous andslightly yellow. Tin content 19.5 per cent calculated.

EXAMPLE 16 Preparation of poly(dibutyltin)4 [trimethylolpropanemonopelargonate di(mercaptopropionate)] 3.0 (isooctylthioglycolate )2 Aquantity of trimethylolpropane monopelargonate di(mercaptopropionate),(69.5 grams), was mixed with 49.6 grams of dibutyltin oxide, 21 grams ofisooctylthioglycolate and the whole heated at 100 C for three hours inthe presence of refluxing benzene. Removal of water was complete after1.5 hours. Benzene was removed by heating under reduced pressure and theproduct filtered to give a viscous oil with specific gravity at 25 C of1.181. Tin content 17.2 per cent calculated.

EXAMPLE 17 Preparation of poly(dibutyltin )2.0 [trimethylolpropanemono-pelargonate di(thioglycolate)] 1.0 (lauryl thioglyco- 1ate)2.0

A quantity of trimethylolpropane monopelargonate di(thioglycolate), (240grams), was combined with 248 grams of dibutyltin oxide, 267 grams oflauryl thioglycolate and the mixture heated at 100 C for 2.5 hours. Theproduct was filtered and benzene removed by heating under reducedpressure, leaving a viscous oil with specific gravity at 25 C of 1.120.Tin content 19.08 weight per cent.

EXAMPLE 18 Preparation of poly(dibutyltin)2.0 [trimethylolpropanemono-pelargonate di(thioglycolate)] 1.0 (isooctylthioglycolate)2.0

A quantity of trimethylolpropane monopelargonate di(thioglycolate),(42.5 grams) was combined with 49.5 grams dibutyltin oxide, 84 gramsisooctylthioglycolate and the mixture heated at 94 C for four hours inthe presence of refluxing benzene. Removal of water was complete afterone hour. Filtration and removal of benzene by heating under reducedpressure left a very pale yellow oil. Tin content 13.6 weight per cent,calculated. Specific gravity at 25 C 1.100.

EXAMPLE 19 Preparation of poly(dibutyltin)l.0 [pentraerythritoldipelargonate di(thioglycolate)] 1 .0

A 500 ml. three-neck flask fitted with thermometer and nitrogen spargetube was charged with 68.5 grams pentaerythritol, 158 grams pelargonicacid, 83 grams thioglycolic acid, 100 ml. benzene and 0.5 grams methanesulfonic acid. The mixture was refluxed and water of condensationremoved for 9.5 hours at 95 to 150 C. After cooling the flask, 132 gramsof dibutyltin oxide was added and heating at 115 C continued for ninehours. Removal of water was complete after three hours reaction time.Benzene was removed by heating under reduced pressure leaving a lightlyviscous and slightly yellow product. Calculated tin content is 11.9weight per cent.

EXAMPLE 20 Preparation of poly(di butyltin)4.0[pentaerythritol(pelargonate)2.0 (mercaptopropionate) 1 .6150

A quantity of pentaerythritol pelargonate mercaptopropionate (100grams), was combined with 35.4 grams dibutyltin oxide and the mixtureheated at 100 C for 2.5 hours in the presence of refluxing benzene.Water was removed as formed. Benzene was removed, after filtration, byheating under reduced pressures, to give a viscous oil product, specificgravity at 25 C 1.140. Tin content 12.5 per cent (calculated).

EXAMPLE 21 Preparation of poly(dibutyltin), [pentaerythritol(pelargonate) 2.0 (mercaptopropionate)1.6] 1.0(isooctylthioglyc0- late)1.7

A quantity of (pentaerythritoU (pelargonateh (mercaptopropionate) (126grams), was combined with 95.7 grams dibutyltin oxide and the mixtureheated at 100 C in the presence of refluxing benzene. Water was removedas formed. After five hours, the mixture was cooled, 81 grams ofisooctylthioglycolate were added and reflux at 100 C continued for twohours. Benzene was removed by heating under reduced pressure and theresidue filtered to give a pale yellow product. Specific gravity at 25 C1.090. Tin content 15.9 per cent calculated.

in order to compare the stabilizing effectiveness of the mercaptidecondensation polymers of the present invention with a referencestabilizing material of the organotin type widely used in industry priorto this invention, oven tests of polyvinyl chloride resin stabilizedwith the various stabilizing compositions were conducted. Simple poly(vinyl chloride) formations containing polyvinyl chloride homopolymer,the stabilizer and mineral oil lubricant were premixed in a Hobart mixerand milled for five minutes at 325 F on a two roll differential speedmill. The resin was then sheeted off and samples of the sheets werecompared in thermal stability by heating at 400 F in a circulating airoven. Samples were removed for visual comparison at minute intervals.Progressive thermal degradation was indicated by a progressive darkeningfrom a very slightly yellow color to black. The results of these oventests are set forth in Tablel.

TABLE 1 Own slnlvilily lvsls lnrls Minnics nl 1110 l.

Mini-ml No. lzu'ls l\'( 3 oil l0 '10 30 10 50 6 2 1.5 \'h\' S'l ll 2.2100 1.5 VSY Y li 2.0 100 1.5 \'S\' Y 11 2.0 100 1.5 SY B 2.0 100 1.5 VSYSY Y 1; .2. 2 100 1. 5 SY Y Y 11 2.0 100 1.5 SY Y Y B 2.0 100 1.5 SY Y YB 2.0 100 1.5 SY Y Y B 2.0 100 1.5 VSY SY Y L 2.0 100 1.5 VSY SY Y B 2.0100 1.5 VSY Y 13 2.0 100 1.5 SY Y B 3.0 100 1.5 SY B 2.0 100 1.5 Y B 212.0 100 1.5 VSY SY Y B Reference 2.0 100 1.5 VSY SY Y B l Refers to thecondensation polymers produced in the several exumples hereinbofore setforth.

2 Refers to simple poly(vinyl chloride) homopolymer formulation used inthe tests.

1 In the even tests, degrees of thermal degradation have been evidencedlzy glsllffvery slightly yellow, SY=slight1y yellow, Y=yellow, and

The reference stabilizing composition used was dibutyltin-5,5-bis (isoocLlthioglycolate).

EXAMPLE 22 Preparation of poly( dibutyltin) (pentaerythritol pelargonatebenzoate dithioglyco1ate), (isooctylthioglycolate A reaction mixturecontaining 136 grams pentaerythritol, grams pelargonic acid, 122 gramsbenzoic acid and 233 grams thioglycolic acid was heated at 135 C in thepresence of 0.5 gram p-toluene sulfonic acid catalyst and sufficientbenzene to give reflux and efiicient removal of water formed during thereaction. After nine hours, all water of reaction was removed. Excessacids were removed by reduced pressure distillation and washing of theresidue with aqueous sodium carbonate. Drying with vacuum and heat lefta yellow oil with specific gravity at 25 C of 1.178. Mercaptan sulfurcontent 15.75 weight per cent.

A portion of this product (83 grams) was combined with 100 gramsdibutyltin oxide and 82 grams isooctylthioglycolate and the resultingmixture heated for two hours at 100 C in the presence of refluxingbenzene. The product was filtered and benzene removed by heating underreduced pressure to give 254 grams of a light yellow oil with specificgravity at 25 C of 1.186. Calculated tin content 18.2 weight per cent.

EXAMPLE 23 Preparation of poly(dibutyltin), [(pentaerythritol),(pelargonate), (mercaptopropionate), 1,0 (isooctylthioglycohs A reactionmixture containing 148 grams pentaerythritol, 192.5 gramsmercaptopropionic acid and 276.5 grams pelar gonic acid was heated at Cin the presence of refluxing benzene. All water of reaction was removed.Volatiles were removed by nitrogen sparge and reduced pressure to leave550 grams of a pale yellow oil containing 10.7 weight per cent mercaptansulfur. 1

A portion of this product (212 grams) was combined with 124 gramsdibutyltin oxide, 63 grams isooctylthioglycolate and heated for twohours at 100 C in the presence of refluxing benzene. Removal of waterwas complete after one, hour. Benzene was removed by heating underreduced pressure and the product filtered to give a viscous yellow oilwith viscosity at 25 of 858 cs. and specific gravity at 25 C of 1.15.Calculated tin content 15.1 weight per cent.

EXAMPLE 24 Preparation of poly(dibutyltin)2.0 [trimethylolpropanepelargonate di( thioglycolate)] 1.0 (phenoxyethylthioglycolate)2.0 Amixture of l 10 grams trimethylolpropane monopelargonatedi(thioglycolate), 124 grams dibutyltin oxide, and 105 gramsphenoxyethylthioglycolate was heated for three hours at 100 C in thepresence of refluxing benzene. During this time, 9 ml. of water wasremoved from the reaction. Removal of benzene by means of reducedpressure and nitrogen purge left 338 grams of a viscous yellow oil withspecific gravity at 25 C of 1.257. Calculated tin content 17.8 weightper cent.

EXAMPLE 25 Preparation of poly(dibutyltin)2.0 trimethylolpropanepelargonate di( thioglycolate 1 .0( isooctylthioglycolate)2.0

A mixture of 125 grams dibutyltin oxide, 110 grams trimethylolpropanemonopelargonate di(thioglycolate) and 102 grams isooctylthioglycolatewas heated for two hours at 105 in the presence of refluxing benzene.During that time, 7 ml. of water was removed from the reaction.Evaporation of benzene and filtration of the residue left 328 grams of apale yellow oil product. Calculated tin content 18.1 weight per cent.

EXAMPLE 26 Preparation of (pentaerythritol) l .0(pelargonate)2.0(mercaptopropionate) l .6

A three-liter flask equipped with thermometer, and nitrogen sparge tubewas charged with 444 grams pentaerythritol, 596 25 gramsmercaptopropionic acid, 950 grams pelargonic acid and 100 grams benzene.The flask was attached to an esterification apparatus, consisting of acolumn, Dean Stark water separator and totalreflux condenser. Heat wasapplied to the kettle and the benzene concentration adjusted to givereflux and efiicient removal of water at 180 C kettle temperature.Reaction was continued at that temperature for twelve hours. Benzene wasremoved with vacuum to leave 1790 grams residue product.

Excess acid was removed by steam distillation and the product 35 driedwith vacuum to leave a pale yellow oil polymercaptoester productcontaining 9.72 per cent by weight mercaptan sulfur.

EXAMPLE 27 Preparation of poly( dibutyltin )2.0 pentaerythritol)(pelargonate) mercaptopropionate) l. 75] 1 .6( phenoxyethylthioglycolate) 1.2

A mixture of- 125' grams dibutyltin oxide, 63 gramsphenoxyethylthioglycolate and 230 grams polymercaptoester from Example26 was heated for two hours at 100 C in the presence of refluxingbenzene. During this time, 7 ml. of water was removed from the reaction.Evaporation of benzene solvent with nitrogen purge and reduced pressureand filtration left 410 grams of a yellow oil product with specificgravity 25 C) 1.179. Calculated tin content 14.3 weight per cent.

EXAMPLE 28 Preparation of poly(dibutyltin )2.0 [(pentaerythritol) l .0pelargonate) l 75(mercaptopropionate) l .75 l .6( n-dodecyl mercaptide)l .2

A mixture of 125 grams dibutyltin oxide, 230 grams polymercaptoesterfrom Example 26 and 61 grams primary ndodecyl mercaptan was heated fortwo hours at 100 C in the presence of refluxing benzene. During thattime, 7 ml. of

10 water was removed from the reaction. Evaporation of benzene andfiltration left 409 grams of a pale yellow oil product with specificgravity C) of 1.130 and viscosity (25 C) of 1508 cs. Calculated tincontent 14.4 weight per cent.

EXAMPLE 29 EXAMPLE 3O 0 Preparation of poly(dibutyltin)2.0[(pentaerythritol)l.0

(pelargonate) 1.8 tylthioglycolate) 1 .2

A mixture of 125 grams dibutyltin oxide, 230 grams polymercaptoesterfrom Example 26 and 63 grams isooctylthioglycolate was heated for twohours at 100 C in the presence of refluxing benzene. During that time, 7ml. of water was removed from the reaction. Evaporation of benzene andfiltration of the residue left 405 grams of a pale yellow oil having aspecific gravity of 1.143 (at 25 C) and viscosity 25 i C) of 982 cs.Calculated tin content 14.6 weight per cent.

(mercaptopropionate) 1 7S l .6( isooc- EXAMPLE 31 Preparation of poly(dibutyltin)2.0 [(pentaerythritol) l .0 (pelargonate)2.0(mercaptopropionate)1.8] 1.1(phenoxyethylthioglycolate )2.0

A mixture of 125 grams dibutyltin oxide, 170 grams polymercaptoesterfrom Example 26 and 110 grams phenoxyethylthioglycolate was heated forthree hours at 1 10 C in the presence of refluxing benzene. During thattime, 8 ml. of water was removed from the reaction. Evaporation ofbenzene and filtration of the residue left 399 grams of a pale yellowoil TABLE 11 Compound composition Oven stability tests 3 Stabilizer tincontent Example 1 Parts Minutes at 375 F. wt. percent, No. Parts PVC 2Mineral oil 10 20 40 6O .IO ealc.

2 100 l. 5 0 1 1 2 2 2 3 l8. 2 2 100 1. 5 O 1 1 2 2 3 3 15. 1 2 100 1. 50 1 1 2 2 2 3 17. 8 2 100 1. 5 0 1 1 2 2 2 3 1S. 1 2 100 1. 5 0 1 2 2 23 4 18. t1 2 100 1. 5 0 1 1 2 2 3 18. 2 2 100 1. 5 l) l 2 2+ 3 4+ 15. 12 100 l. 5 l) 1 1 1+ 2 2+ 3 18. 1 2 100 1. 5 0 1 1+ 2 2 3 4 11. 3 2100 1. 5 0 2 2 2 2+ 3 4 14. 4 2 100 l. 5 0 2 2 2 2+ 3 4 15. 2 2 100 1. 5l) l 2 2 2+ 3 4 14. 6 2 100 1. 5 0 1 1+ 2 2 2 3 18. 6 2 .2 100 0. 5 0 11 1+ 2 2 3 17. 8 27. 2.65 100 l). 5 0 1 1+ 2 2 3 14.6 21). 2. 5 100 0. 51 1+ 2 2 2 3 15. 2 31 2 45 100 0. 5 0 1 1+ 2 2 3 l5. 1 31 2 100 (l. 5 ll1 1+ 2 2 3 3+ 15. l Referenee 2 100 0. 5 0 1 1+ 2 2 3 3+ 18. 6 2 2 11)!)0.5 1+ 1+ 2 2 3+ 5 14.3 2 100 0. 5 1 1 2 3 4 5 l4. 1 2 100 0. 5 1 1+ 1+2 2 3+ 5 15. 2 31 2 100 0.5 l) 1 1 2 2 3 4 15.1 Reference 2 100 0. 5 ll1 l 2 2 3 t 15.11

l Refers to the condensation polymers produced in the sever-n1 exampleslwrvinheforu set. forth. 2 Refers to simple poly(vinyl chloride) howpolymer formulation used in the :sts.

3 Numbers represent inert-using color: ll=colorless, l=lirst notieiihleyellow, 5= hlnek.

4 The reference stabilizing composition used was rlihutyltin -5,5-lns(lsoocLyltluoglycolnte).

with specific gravity (25 C) of 1.206 and viscosity (25 C) of 300 cs.Calculated tin content 15 weight per cent.

The stabilizing compositions produced in Examples 22-31 were subjectedto oven testing in a manner similar to the oven testing of the productsof Examples 6-21 as reported in Table 1, except that the tests werecarried out at a temperature of 375 F for a total period of 100 minutes.In Table 11 the results of these latter tests are tabulated and a numbersystem is used to indicate color shadings resulting from thermaldegradation. Also the tin content of all samples, including thereference sample, is set forth for comparison purposes. I

From the tabulated data in Tables I and 11, it will be apparent that thestabilizing compositions of the present invention are highly effectivein their thermal stabilizing properties for polyhaloresins. Aspreviously indicated, the processing characteristics, such as fusiontime and lubricity, of the stabilized polyvinyl chloride formulationscan be controlled and selectively varied by varying the structure of thestabilizer additive. This selective variation of processingcharacteristics, however, has been found to be independent of the tincontent of the formulations.

The stabilizing compositions of the invention can be utilized in awidely varying range of concentration in the stabilization of resinsderived from polyvinyl halide resins, such range embracing from about0.1 weight per cent to about 10 weight per cent. While this range isoperative in the case of the polyvinyl halide resins, it is herepreferably to use the stabilizers in concentrations of from about 0.5weight per cent to about weight per cent, and most preferably from about1.5 to about 3 weight per cent.

In addition to the incorporation of the stabilizing compounds of theinvention in resinous formulations of the type described, theseformulations may also contain conventional plasticizer materials, suchas phthalates, adipates and epoxy esters, lubricants such as calciumstearate, hydrocarbon waxes, polyethylene synthetic diamide based waxes,pigments and colorants as well as processing or impact modifiers such asABS resins, acrylates, chlorinated polyethylenes, hydrocarbon resins,etc.

Although certain specific embodiments and examples of the invention havebeen described herein in order to provide illustrations of typicalpractice of the invention, it will be apparent that variousmodifications in the cited reactants and reaction conditions can be madewithout departure from the basic principles of the invention. All suchmodifications are deemed to be circumscribed by the spirit and scope ofthe invention except as the same may be necessarily limited by theappended claims or reasonable equivalents thereof.

What is claimed is: 1. A condensation polymer of the formula:

wherein X is an alkylene-substituted acyl radical in which alkylenecontains from 1 to 6 carbon atoms, Y is a saturated aliphatichydrocarbon radical containing from 3 to l 1 carbon atoms, m is a wholenumber greater than 1, n is a number from 1 to 6, R is alkyl of 4 to 8carbon atoms, R is selected from the group consisting of hydrogen and anacyl radical derived from an organic acid selected from the groupconsisting of a saturated aliphatic monocarboxylic acid and an aromaticmonocarboxylic acid, and R is the residue formed by the removal ofacidic hydrogen from a member selected from the group consisting of analkyl mercaptan, a mercaptoalkanoic acid, a mercaptoalkanoic acid ester,an aliphatic monocarboxylic acid, and an aromatic monocarboxylic acid.

2. The composition of claim 1 in which R is butyl.

3. The composition of claim 1 in which said condensation polimer iscross-linked with an aryl di-isocyanate.

' The composition of claim 1 in which Y is the hydrocarbon moiety ofpentaerythritol.

5. The composition of claim 1 in which X S is the moiety of amercaptoalkanoic acid containing from 1 to 6 carbon atoms.

6. The composition of claim 5 in which the mercaptoalkanoic acid ismercaptopropionic acid.

7. The composition of claim 1 in which R is the residue formed by theremoval of acidic hydrogen from pelargonic acid.

8. Poly(dibutyltin) 2.0 (pentaerythritol pelargonate benzoatedithioglycolate) 1.0 (isooctylthioglycolate) 2.0, the numeralsindicating molar proportions.

9. Poly(dibutyltin) 2.0 [(pentaerythritol) 1.0 (pelargonate) 2.0(mercaptopropionate) 1.8] 1.1 (phenoxyethylmercaptopropionate) 2.0, thenumerals indicating molar proportions.

l0. Poly(dibutyltin) 2.0 [(pentaerythn'tol) 1.0 (pelargonate) 1.75(mercaptopropionate) 1.75 1.14 (n-dodecylmercaptide) 2.0, the numeralsindicating molar proportions.

11. Poly(dibutyltin) 2.0 [trimethylolpropane pelargonatedi(thioglycolate)] 1.0 (phenoxyethylthioglycolate) 2.0, the numeralsindicating molar proportions.

12. Poly(dibutyltin) 2.0 [pentaerythritol monohydroxy monopelargonatedi(mercaptopropionate)] 1.0 (lauryl thioglycolate) 2.0 (toluene-2,4-diisocyanate) 0.6, the numerals indicating molar proportions.

2. The composition of claim 1 in which R is butyl.
 3. The composition ofclaim 1 in which said condensation polymer is cross-linked with an aryldi-isocyanate.
 4. The composition of claim 1 in which Y is thehydrocarbon moiety of pentaerythritol.
 5. The composition of claim 1 inwhich X - S is the moiety of a mercaptoalkanoic acid containing from 1to 6 carbon atoms.
 6. The composition of claim 5 in which themercaptoalkanoic acid is mercaptopropionic acid.
 7. The composition ofclaim 1 in which R'' is the residue formed by the removal of acidichydrogen from pelargonic acid.
 8. Poly(dibutyltin) 2.0 (pentaerythritolpelargonate benzoate dithioglycolate) 1.0 (isooctylthioglycolate) 2.0,the numerals indicating molar proportions.
 9. Poly(dibutyltin) 2.0((pentaerythritol) 1.0 (pelargonate) 2.0 (mercaptopropionate) 1.8) 1.1(phenoxyethylmercaptopropionate) 2.0, the numerals indicating molarproportions.
 10. Poly(dibutyltin) 2.0 ((pentaerythritol) 1.0(pelargonate) 1.75 (mercaptopropionate) 1.75 ) 1.14(n-dodecylmercaptide) 2.0, the numerals indicatiNg molar proportions.11. Poly(dibutyltin) 2.0 (trimethylolpropane pelargonatedi(thioglycolate)) 1.0 (phenoxyethylthioglycolate) 2.0, the numeralsindicating molar proportions.
 12. Poly(dibutyltin) 2.0 (pentaerythritolmonohydroxy monopelargonate di(mercaptopropionate)) 1.0 (laurylthioglycolate) 2.0 (toluene-2, 4-diisocyanate) 0.6, the numeralsindicating molar proportions.